CABALA_Diet & Health
CirculAting Bile Acids as biomarkers of metabolic health - Linking microbiotA, Diet and Health
Background and aim
Bile acids (BA) through G protein-coupled bile acid receptor 1 (GPBAR1 or TGR5) and nuclear receptors like Farnesoid X receptor (FXR) regulate mammalian inflammation, and lipid, glucose, energy, and xenobiotic metabolism. The gut microbiota modulates the enterohepatic circulation of BA and microbially produced secondary BA appear to be more potent receptor agonists than primary BA, providing a mechanistic link between microbiome structure/function and regulation of host physiology. Evidence mainly from animal studies shows that dietary fibers and polyphenols and exercise can impact on BA metabolism. Similarly, certain bile salt hydrolysing (BSH) bacteria modulate circulating bile acid (CBA) profiles and strongly influence cholesterol uptake. However, human data confirming dietary modulation of CBA profiles and subsequent regulation of physiological homeostasis remains elusive. Using samples from the RoCAV cohort and existing randomised control trials (RCT), we correlated CBA profiles with Mediterranean (MED) diet adherence and measures of metabolic health. In a bespoke short-term RCT we measured the effect of Limosilactobacillus reuteri NCIMB 30242 (BSH positive probiotic), oats (prebiotics) and Renetta Canada apples (polyphenol rich) on CBA and demonstrated that L. reuteri could increase host postprandial unconjugated and hydrophobic CBA profiles, and that oats and apples may modulate cardiovascular disease (CVD) risk markers in both chronic and acute settings. In a long term (18 month), large-scale (n=300) existing dietary and lifestyle intervention, we demonstrated how a polyphenol rich green-MED diet and exercise promotes metabolic health in prediabetics through modulation of the gut microbiota and CBA signalling (DIRECT-PLUS study). Finally, we modelled BA profiles or metabotype with microbiome signatures and BA biotransformation potential using high-resolution metagenomics and established the molecular basis of BA regulation of immune and metabolic homeostasis by measuring the relative receptor activation potential of individual CBA and BA-metabotype profiles using novel pre-clinical human cell-based reporter systems. CABALA_diet&health has provided direct evidence in humans that CBA profiles influence CVD risk supporting their consideration as biomarkers of health, related to the microbiome and modulated by diet and exercise. We have also demonstrated in humans, that autholgous faecal microbiome transfer, after green-MED dietary intervention retards weight regain and maintains metabolic health. Moreover, we propose that global BA species diversity may be an indicator of health and bile acid convergence a function of disease, and additionally, that lowering total CBA concentrations may be a viable target for improving metabolic health at the population level
- Scientific Impact.
CABALA_DIET&HEALTH aimed to improve our understanding of the fundamental link between nutrition and CBA profiles, key signalling molecules considered to be involved in regulating host metabolic and immune homeostasis, and potential biomarkers of health status. We believe this improved understanding will unravel a rational scientific basis for healthy eating guidelines, providing the European consumer the opportunity to make informed choices when building their diets from a variety of foods. It will provide the European food industry with key knowledge on how specific food ingredients regulate BA profiles and identify new targets to improve the foods we eat. Finally, we believe it will also deliver health care providers with a validated biomarker of the long-term trajectory from health to chronic diet/life-style associated disease. Our project will maximise the knowledge and investment from existing initiatives for example RoCAV cohort, and create synergies with relevant initiatives in particular the JPI Biomarker projects FOODBALL, SALIVAGES and VALID which members of this consortium are directly linked or where collaborations have been formed during the present project. This project also provided a multidisciplinary, trans-omics and inter-sector training for early stage researchers, thereby supporting European scientific/clinical/industrial research infrastructure. This will ensure that a critical mass will be achieved which will contribute to the JPI’s vision of improving public health through dietary strategies and a more informed society.
- Health-related applications and/or new products
CABALA_diet&health has the potential to provide the scientific mechanistic data linking key components of the Mediterranean style diet, and healthy eating guidelines across Europe. Specifically, we show that intake of foods rich in fermentable fibers, polyphenols and probiotics, can modulate circulating bile acid profiles and impact on metabolic health. The project contributes the scientific support for rational selection of probiotics and other functional ingredients, which can then be incorporated into new foods to improve metabolic health at the population level. The project also supports existing whole foods and diets already rich in fibers and polyphenols, also supporting existing healthy eating guidelines. The aim is to improve adherence to healthy diets by promoting consumption of fiber/polyphenol/probiotic rich foods and providing the scientific basis for designing new foods.
|University Of Reading
|University College Cork
|University of Insubria
Diet-microbe-gut health dialogue centers on bile acid (BA) activation of signaling receptors in dictating both metabolic and health status. Our work indicates global diversity as an indicator of health, bile acid convergence is a function of disease. In Cork Ireland, we have determined, through cellular systems, signaling and gene expression overlap along with independence of process between three bile acid receptors (FXR, VDR, TGR5), functionally and regionally. Finally, bile acids are emulsifiers of lipid. Our work has shown that lipids can act as a sequesterants of certain bile acids negating their signaling effects, at the level of gene expression and cell organelle fitness.
We have demonstrated, in a bespoke mixed chronic and acute postprandial challenge dietary intervention conducted in Reading UK, that functional foods specifically, oats (prebiotic), polyphenol rich apples (Renetta Canada apples) and a BSH positive probiotic, (Limosilactobacillus reuteri NCIMB 30242), can influence post prandial circulating BA (CBA) profiles on an individual basis but may mediate their respective health effects via different mechanisms, especially during the postprandial phase. Apples reduced fasting apoB, a marker of low-density lipoprotein cholesterol (an independent CVD risk factor), and both oats and apples influenced postprandial glycaemic control and triacylglycerol response. L. reuteri had a significant effect on postprandial secondary CBA concentrations.
From the RoCAV cohort study in Varese Italy, we confirmed that diet was associated with CBA profiles, which were in turn associated with metabolic health. Specifically, high levels of CBA were associated with unhealthy metabolic parameters, whereas high levels of the BA responsive hormone FGF-19 was confirmed to be associated with reduced HOMA index and waist-to-hip ratio.
In the DIRECT-PLUS dietary intervention with a polyphenol enriched Mediterranean diet conducted at the Ben Gurion University of the Negev in Israel, 6 month weight loss could be directly attributed to dietary microbiota modulation. Moreover, total CBA concentrations positively correlated with metabolic disease risk factors and autochthonous faecal microbiome transplant (aFMT) after green-MED diet microbiome modulation retarded weight regain over an 8 month follow up and maintained metabolic health.
Strong correlations between individual CBA species or ratios with individual bacterial taxa were rare within the datasets and not consistent between different studies. Correlations between CBA profiles and enterotype-like community structures were apparent but not conserved across different data-sets. Microbial BA metabolism may therefore be more correctly considered as a community activity, possibly with different taxa performing similar chemical conversions in different individuals. Shotgun and strain level analysis did not resolve CBA:taxa associations but revealed relatively low prevalence and abundance of BA metabolizing genes across samples, suggesting a gap in knowledge concerning annotation of microbial BA metabolising genes.
Author: Duc H. Le
Author: Golubeva AV, Joyce SA, Moloney G, Burokas A, Sherwin E, Arboleya S, Flynn I, Khochanskiy D, Moya-Pérez A, Peterson V, Rea K, Murphy K, Makarova O, Buravkov S, Hyland NP, Stanton C, Clarke G, Gahan CGM, Dinan TG, Cryan JF.
Author: Rizzetto L, Fava F, Tuohy KM, Selmi C.
Author: Ulaszewska MM, Mancini A, Garcia-Aloy M, Del Bubba M, Tuohy KM, Vrhovsek U.
Author: Fava F, Rizzetto L, Tuohy KM.
Author: Mullish BH, McDonald JAK, Pechlivanis A, Allegretti JR, Kao D, Barker GF, Kapila D, Petrof EO, Joyce SA, Gahan CGM, Glegola-Madejska I, Williams HRT, Holmes E, Clarke TB, Thursz MR, Marchesi JR
Author: Koutsos, A, Riccadonna, S, Ulaszewska, MM, Franceschi, P, Trošt, K, Galvin, A, Braune, T, Fava, F, Perenzoni, D, Mattivi, F, Tuohy, KM, Lovegrove, J.
Author: Ehud Rinott*, Ilan Youngster, , Anat Yaskolka Meir, Gal Tsaban, Hila Zelicha, Alon Kaplan, Dan Knights, Kieran Tuohy*, Francesca Fava*, Matthias Uwe Scholz*, Oren Ziv, Elad Reuven, Amir Tirosh, Assaf Rudich, Matthias Blüher, Michael Stumvoll, Uta Ceglarek, Karine Clement, Omry Koren, Dong D. Wang, Frank B. Hu, Meir J Stampfer, Iris Shai.
Author: Anat Yaskolka Meir,1 Ehud Rinott*,1 Gal Tsaban,1,2 Hila Zelicha,1 Alon Kaplan,1 Philip Rosen,3 Ilan Shelef,3 Ilan Youngster,4 Aryeh Shalev,2 Matthias Blüher,5 Uta Ceglarek,6 Michael Stumvoll,5 Kieran Tuohy *,7 Camilla Diotallevi *,7,8 Urska Vrhovsek*,8 Frank Hu,9,10,11 Meir Stampfer,9,10,11 Iris Shai
Author: Mastrocola R*, Collotta D*, Gaudioso G*, Le Berre M*, Cento AS*, Ferreira Alves G*, Chiazza F*, Verta R*, Bertocchi I*, Manig F*, Hellwig M*, Fava F*, Cifani C*, Aragno M*, Henle T*, Joshi L*, Tuohy K*, Collino M*.
Author: Collotta D, Hull W, Mastrocola R, Chiazza F, Cento AS, Murphy C, Verta R, Alves GF, Gaudioso G, Fava F, Yaqoob M, Aragno M, Tuohy K, Thiemermann C, Collino M.
Author: Lasalvia P, Gianfagna F, Veronesi G, Franchin M, Tozzi M, Castelli P, Grandi AM, Zambon A, Iacoviello L, Ferrario MM.
Author: Prete R, Long SL, Joyce SA, Corsetti A.
Author: Geng W, Long SL, Chang YJ, Saxton AM, Joyce SA, Lin J.
Author: Prete R, Long SL, Gallardo AL, Gahan CG, Corsetti A, Joyce SA.
Author: Ulaszewska MM, Koutsos A, Trošt K, Stanstrup J, Garcia-Aloy M, Scholz M, Fava F, Natella F, Scaccini C, Vrhovsek U, Tuohy K, Lovegrove J, Mattivi F.
Author: Camilla Diotallevi, Giulia Gaudioso, Francesca Fava, Andrea Angeli, Cesare Lotti, Urska Vrhovsek, Ehud Rinott, Iris Shai, Marco Gobbetti, Kieran Tuohy
Author: Rose-Anna G. Pushpass*, Shouq Alzoufairi*, Kim G. Jackson* and Julie A. Lovegrove*
Author: Joyce SA, Kamil A, Fleige L, Gahan CGM.
Author: Sarah Louise Long* and Susan A. Joyce*
Author: Shanalee C James, Karl Fraser, Wayne Young, Phoebe E Heenan, Richard B Gearry, Jacqueline I Keenan, Nicholas J Talley, Susan A Joyce, Warren C McNabb, Nicole C Roy
CABALA_DIET&HEALTH aimed to demonstrate that diet-microbiome interactions in the gut determine circulating bile acid (CBA) profiles and their physiological effects. Our overarching objective was to provide evidence in humans, that CBA may be considered modifiable biomarkers of cardiovascular or metabolic health and disease risk, which are determined by the gut microbiota and respond to diet and life-style intervention. The project has published new analytical methodologies, analyzed data and samples from existing/ongoing studies, including the DIRECT-PLUS study in Israel, developed new pre-clinical in vitro models for measuring CBA cell signaling and completed the CABALA_diet&health dietary intervention study in Reading, UK. It has also generated new models correlating CBA with gut microbiota composition (FEM, USDI), with dietary intake, exercise and with clinical markers of cardiovascular disease (CVD) risk. It has demonstrated that diet, both in chronic and acute postprandial settings influence CBA profiles and that total CBA concentrations and profiles of CBA are inversely related with specific CVD risk biomarkers at a population level (RoCAV study, Varese Italy). CABALA_diet&health has demonstrated and developed new cell based reporter systems at UCC, Ireland, which confirm that different CBA and profiles of CBA can regulate host physiological processes involved in inflammatory and metabolic pathways which govern CVD and metabolic disease risk and moreover, we have shown that major perturbation of the gut microbiota, via diet (DIRECT-PLUS green-MED diet), surgery (three different common bariatric surgeries) and autologous faecal microbiome transplant (aFMT) can modulate CBA, biomarkers of CVD risk and body weight in humans. From our observations we can also propose that global BA species diversity is associated with metabolic and immune health, and that reduced diversity is associated with inflammatory related disease. This project, therefore, has provided strong evidence in humans, that CBA concentrations may be a biomarker of health, modified by diet, exercise and the gut microbiota. It has also provided support that microbiota BA metabolism may play an important mechanistic role in mediating the health effects of the Mediterranean style diet and bioactive foods including oats, apples and probiotics (Limosilactobacillus reuteri NCIMB 30242 ). Further, we have provided new evidence in humans, that the gut microbiota and its BA metabolism, may be an active driver of diet induced weight management, retreat of diabetes upon surgery and major dietary intervention, and that aFMT of a green-MED diet modified microbiome can reduce the risk of weight regain and metabolic rebound following successful diet induced weight loss. Together, data from the CABALA_diet&health projects support the notion that the gut microbiota is not a passive by-stander in obesity and metabolic disease, but an active player in metabolic health. Furthermore, we have also shown that diet and medical interventions known to reduce body weight and improve markers of metabolic disease risk do so in part through their interactions with the gut microbiota and that microbial BA metabolism contributes mechanistically to metabolic health across Domains of life.
CABALA_diet&health therefore provides fundamental new insights into how diet, through the gut microbiota, can shape metabolic and inflammatory related chronic disease risk. This supports JPI-HDHL efforts to tackle the societal challenge of nutrition and health. Specifically, by demonstrating that total CBA concentrations and profiles are related to CVD markers, we provide supportive human observational data of their health biomarker status. By demonstrating that foods and diet, especially healthy high polyphenol diets can regulate total CBA in the long term (DIRECT-PLUS study) and postprandially on an individual basis, we provide support for population level interventions with foods and diets rich in polyphenols and fiber and providescientific support for existing healthy eating guidelines based on the Mediterranean style diet. Similarly, by demonstrating that the gut microbiome, which regulates both the size of the BA pool systemically and the profile of individual BA species in circulation and in faeces, contributes directly to weight loss and improved metabolic health (DIRECT-PLUS ), we provide new supportive data in humans, that microbiome targeted strategies have significant potential to tackle the global burden of overweight, obesity and the diseases of obesity. Healthy dietary guidelines, especially those targeting metabolic and cardiovascular disease, are well established throughout the world but translation to individual lifestyles remains a challenge. Part of the problem is lack of mechanistic understanding of how healthy foods and diets translate into physiological effects in the human body. This has challenged medical uptake of nutrition as an efficacious intervention or even preventative strategy, and left room for confused and contradictory messaging in the general media, contributing to poor uptake of healthy diets at the population level. Similarly, without sound scientific basis of how healthy foods regulate host physiology, the food industry has struggled to provide nutritious foods to serve the challenges of modern lifestyles. However, foods and medical intervention strategies for shaping the gut microbiota are well established, and by providing new insight into how microbiome modulation can shape CBA profiles and total concentrations, and concomitantly influence host physiology, CABALA_diet&health has contributed significantly to providing a rational basis for designing the next generation of functional foods. Future work should help fill gaps in nutrient:nutrient interactions in the gut and how they influence the gut microbiome and BA metabolism; new bioinformatics tools to link new or dual function microbial enzymes to specific chemical reactions in BA metabolism, and a more personalized, genotype based approach towards CBA:BA receptor interactions; and broader application of nutri-kinetics based approaches to demonstrating how foods and diets modulate microbially derived metabolites capable of regulating human metabolic and inflammatory pathways and shown in animal studies to determine chronic disease risk and immune-resilience in the face of pathogen invasion.